Method of forming u-shaped turbine-buckets.



Np. ceases.

UNITEE sTATEs PATENTA oEEioE.

HULDREICE KELLER, or BERLIN, GERMANY, `'AssIcfNoR'ro GENERAL ELECTRIC-COMPANY,

A CORPORATION or NEWl YoRE. 'v

:METHOD oEEoRMINe U-sHArED T'URBINE-:Bucxars Beit known that I, HULDREIOH KELLER, a citizen of Switzerland, residing at Berlin, Germany, 'have invented certain nevir and useful Improvements in Methods of Formin U -Shaped Turbine-Buckets, of which thelfol owing is a specification.

'Certain types of turbines are-provided with wheels or stationary elements or both havinr U-shaped buckets formed in thel curve surfaces-0r in the side faces ofthe .wheels or stationary elements. f

It has been proposed to use a double or step cutter for' thi-s purpose, but practice shows that this cannot be@ done successfully even Where the buckets are symmetrically formed. Where they are unsymmetrically formed it is impossible to form them'in this m3111181'.

The object of the present invention is to im rove the methods of lformingthese s'o` l* cal ed U-shaped buckets.

In practicing the invention the blank, Whether it be a Wheel, rin or segment there of, isrst "machined to t e desired' dirnensionsor approximately thereto, A cut-A away portion -or groove, usually a halfround, is then formed or turned in the sur- ,fa'ce or surfaces intended to be provided with buckets. The cut-away portion .or groove is of such shape,vsize and location that it Will, When'the milling cutter is operating, receive the spindle thereof, and permit the cutter to enter the desired depth in to the stock of theblank. The center of the cut-away portion or `groove registers with the axes of the buckets When the latter are symmetrical in form, and is located at one side thereof When the buckets are unsymmetrical. The Wheel, ring or segment thereof `may beprovided with one'or more rows of bucketswhich have the same or different diameters. Buckets formed irraccordance with the invention may be used in connection Iwith the rotary or stationary partis, or both, of a steam or other elastiefluid turbine. i

In the accompanying drawing, which illustrates the various steps in the manufacture of turbine elements in accordance-'With the invention,^Figure 1 is an axial section of a finished blank suitable for a wheel or stationary element; Figs. 2 and show'elespecificationof Letters Patent. Appueaaqn med November 1e, 1904. serial No. 232,943.

.spindle for which enters the Patnted Aug. 1o, 1909.

' ments with cut-away ortins'therein to re' ceive the cutter spind es; Fi 4 is a section of an element With`finisl1e buckets; and Fig. 5 is a sectional view of an unsymmetrical bucket.

.T he blank 1 is first machined to thepro per size, and shape for the particular purpose intended, as shown in Fig. 1, for example. The metal in the .blank'registering lwith the position .of the spindle of the milling cutter in its. several operating positions is then cut away. This is preferably done by 4turning one or more grooves 2 in the bucket-contain ing portion, as shown m Figs. 2 and 3. The

grooye may be, and preferably is, formed in the same machine and at the same time that. theblank is inished, to save a separate operation and the necessary handling incident' thereto. In Fig. 2 the (rut-away portion i-s V shown in the periphery, and in Figif3 on one' of the side faces.' AObviously the number of these cut-away portions can be duplicated at will, depending only upon the character of the part. .The depth of the cut-away portion or portions depends'upontheangle of each bucket with .respect to a radius, also upon the size and shape of the spindle of the milling cutter. buckets and .U-shaped I passages 3,'as shown in ig. 4 which may be t one With a simple rotary mi ing cutter, thecut-away portion or groove 2 at each operation Inl Flg. 5 is shown .an unsymmetrlcal bucket space, pocket 4or working passage 4. In this case the cut-away portion 5 is, or may be, somewhat larger than before.

Thenext -step is to cut the ockets Vor working What I claim as neW.and desire to secure by Letters Patent of the United States is,

The method of forming U-shaped pockets in turbine w'heels, which consists in cutting a groove in the periphery ofthe wheel at alpasition corresponding to the axesof the prick-- ets, and then forming the pockets by maIlS of a rotary cutter having its shaft corre-- spending With the groove. l y

In witness whereof. I have hereunto set my hand this eighteenth day of Octoben1904.

' HU'LDREICHl KELLER.

Witnesses: y

HENRY HASPER, WOLDEMAR HAUPT.' 

